Approximately 8% of all newborns risk permanent neurotoxic brain injury due severe neonatal jaundice (SNJ). This condition, generally occurring in the first two weeks of life, is almost always cured with high- intensity blue light phototherapy In the United States, most phototherapy is delivered in a neonatal intensive care unit (NICU) or inpatient nursery because effective, high-intensity devices are designed for that environment. This current care practice has the undesirable consequence of separating mothers and babies during a developmentally vulnerable time while breastfeeding is being established. Approximately 250,000 otherwise well newborns require phototherapy each year. The annual estimated health care cost for treating SNJ in hospitals is in excess of $200 million. Little Sparrows Technologies LLC has developed the Bili-Hut a novel, collapsible, high-intensity, radial array phototherapy device for home use. Current phototherapy devices sufficiently portable for home use do not deliver adequate phototherapy to meet the current American Academy of Pediatrics recommendations for high intensity phototherapy. Once optimized, the Bili-Hut will meet current phototherapy standards and eliminate the need hospital readmissions for otherwise well babies. This could significantly reduce the stress to the mother-baby pair during treatment, at a substantially reduced cost. The goal of this proposal is creation of a next-stage Bili-Hut prototype demonstrating equivalent or superior phototherapy to the market-leading NICU phototherapy device. This will fill an unmet need for an effective home care option. We will achieve this goal by comparing the Bili-Hut efficacy against that of the Natus neoBlue(R) with a benchmark two-dimensional assay, and a novel-three dimensional baby contour assay that is expected to demonstrate the superiority of radial light delivery in maximizing body surface area exposure. An iterative design process will be influenced by these assay results so that the Bili-Hut's light array, radius of curvature and distance from patient can be optimized for highest possible therapeutic effect. Innovations in this project include a collapsible, radial array, high intensity phototherapy device designed for home use, and a predicted relative efficacy based on a novel baby contour assay. Phase I studies will culminate in a refined prototype to guide industrial design of a device for home treatment of SNJ. Our new assay will provide a theoretical framework for designing clinical trials to test high intensity phototherapy over an increased skin area.